The thing is that the SGC wants effective weapons, which staff type weapons are not. Most likely, Area 51 would try to make a scaled up version of the Kull Warrior wrist guns, which were a lot more effective as a weapons system than the bog standard staff cannon, and refit them on to existing platforms. The problem is that Area 51 seems to be building everything, so probably they can't free up so space to build Tau'ri Jumpers. Not to mention the fact that they might not be as responsive as Ancient built Jumpers in terms of deceleration (which is real important when you need to stop before you hit the Control Room).